The European Organization for Research and Treatment of Cancer (EORTC) was established in 1962 to develop, conduct, coordinate and stimulate research on the experimental and clinical bases of cancer treatment in Europe. In 1974, the data management and statistical center (EORTC Data Center) of the organization was created with support from the NCI. The EORTC Data Center provides logistic and scientific support (data management, statistics and medical) to 21 EORTC Clinical Research Groups with respect to the management of clinical trials and related research projects. The Data Center has also developed a large expertise in regulatory affairs and safety dealing with more than 35 countries with different laws and regulations. The Data Center is also a research center involved in: the development of telematics applications to support tissue research (Virtual Tumor Bank), the methodological aspects of clinical trials at various levels (surrogate endpoints, meta-analysis, quality of life, RECIST, treatment outcome), and the development of European and national policies dealing with human research. The EORTC Data Center greatly facilitates collaboration between cooperative research groups providing support in the organization and conduct of large intergroup trials. The aim of this competing continuation grant application is to request continuation of the support that the EORTC Data Center has received without interruption since 1974 so that it can pursue, reinforce and expand the range of services which it offers to the well established network of investigators participating in the activities of the EORTC Clinical Research Groups.